#taiji {
    width: 100px;
    height: 100px;
    transform: rotate(0deg);
    transform-origin: center;
    animation: taiji 40s linear infinite;
    /*Safari 和 Chrome:*/
    -webkit-animation: taiji 40s linear infinite;
}

@keyframes taiji {
    from {
        transform: rotate(360deg);
    }
    to {
        transform: rotate(0deg);
    }
}

@-webkit-keyframes taiji {
     from {
        transform: rotate(360deg);
    }
    to {
        transform: rotate(0deg);
    }
}

div #taiji-1-wilte, div #taiji-1-black {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    position: absolute;
    z-index: -1;
    top: 0px;
    right: 0px;
}

#taiji-1-wilte {
    background: #f1f1f1;
}

#taiji-1-black {
    background: #111;
    clip: rect(0px, 100px, 50px, 0px);
}

#taiji-2-black, #taiji-2-wilte {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    z-index: 2;
    top: 25px;
    right: 0px;
    position: absolute;
}

#taiji-2-black {
    background: #111;
    right: 50px;
}

#taiji-2-wilte {
    background: #f1f1f1;
}

#taiji-3-black, #taiji-3-wilte {
    width: 25px;
    height: 25px;
    border-radius: 50%;
    position: absolute;
    top: 35px;
    right: 12.5px;
    z-index: 3;
}

#taiji-3-wilte {
    background: #f1f1f1;
    right: 62.5px;
}

#taiji-3-black {
    background: #111;
}